Her period of research, studying the muscle regenerating capacity of human bone marrow derived stem cells, led to being an awarded an MD in 2008.

Dr Merrison is the clinical lead for the South West Neuromuscular Operational Delivery Network and the Director of the Bristol MND Centre. These are both regional services offering holistic, specialist care as close to home as possible; crossing traditional boundaries of health and social care and organisational divides.

Dr Merrison is also a Fellow of the Royal College of Physicians and a member of the Association of British Neurologists Neuromuscular Disease Specialist Interest Group; setting standards and publishing guidelines for the care of people living with Neuromuscular conditions in the UK.

Dr Merrison is a board member of the NHS England Neurosciences Clinical Reference Group and the South West Clinical Senate. She is also the NHS England Improving Value Lead for Neurosciences.